The need for increased dialogue and understanding between oyster suppliers and oyster restoration practitioners is a common theme at NORA meetings. The Secretariat are therefore pleased to share the following interview with Raimund Weber of the Orkney Shellfish Hatchery. The posting of this blog should not be interpreted as an endorsement by NORA of the Orkney Shellfish Hatchery. Please visit the NORA Expert Database for an overview of all native oyster suppliers currently registered as supplying native oysters for restoration purposes. We encourage restoration managers to contact their local hatcheries as early as possible in the planning process to provide adequate lead time for production planning and to develop an understanding of the restoration requirements and the production constraints.
1. Which species does the Orkney Shellfish Hatchery work with?
On the macro side, we work with the native oyster, Ostrea edulis, and the European lobster, Homarus gammarus. On the micro side, we culture various algal species for the oysters, and then Artemia salina for the lobster juveniles.
2. What do you think of the recent surge in native oyster restoration efforts around Europe?
Justified! I (we) may only have been involved in this field for a short time, but the benefits are just too important to ignore; and to see our efforts and commitment being echoed by substantial restoration initiatives means we are on the right track. The support by NORA and similar groups have also benefitted the momentum immensely by providing core meetings and conferences where various aspects of the whole are interrogated and analysed.
3. What has been your experience in getting the native oysters to spawn?
I think the anecdotal warnings we received at the outset were overdone. As Ostrea edulis is not a broadcast spawner, such as Crassostrea gigas, I do see that a greater investment is needed for successful rearing of larvae than with C. gigas; however, the upside is that when the larvae are released, they are robust and capable swimmers. I also feel that the importance of the right feed cannot be stressed enough – without the right nutrients to fuel successful gametogenesis and metamorphosis one will become unstuck; hence our investment in two 1250L photobioreactors. These are then topped up with other bag cultured algae species to provide variation in their diet and this choice is also size-palatability related.
4. Where does OSH source their broodstock from?
A private Bonamia-free concern.
5. Does OSH work with spat on shell or cultchless spat?
Currently we are utilising 250micron cultch during the downwelling phase but the option for spat on shell has numerous advantages for the restoration market, so it’s a product we hope to offer in the future.
6. What is the Bonamia status of the hatchery and how does the hatchery view the Bonamia issue?
Our hatchery is Bonamia free. Broodstock are tested for Bonamia by the FHI before they are accepted onto the island and the spat are then again tested for Bonamia before they leave the hatchery.
As to the Bonamia issue, we are ardent supporters of R&D into the optimisation of non-destructive testing for the notifiable diseases. Current destructive methodologies are ill-suited to a species with such low density and scattered populations.
7. To what size can OSH produce biosecure spat? And is there the option of some grow out?
We are targeting the 4mm size range of single spat for the moment. Grow out to larger sizes would be considered should the market investigation support that.
8. What would the first steps be for someone interested in sourcing oysters from OSH for a restoration project?
Best medium for queries is via email, on email@example.com
9. What is your favourite thing about the native oyster?
Marine bioengineer: has filtration superpowers, and the fact that the female broods her larvae. They also have loads of character!